Torres hopes to resume training in around three weeks after scans revealed he had strained rather than ruptured the medial ligaments in his left knee early in Tuesday's thumping Champions League victory at Steaua Bucharest. That would potentially see him available for the visit of Manchester City to Stamford Bridge on 27 October, a Premier League fixture he would have missed had the FA banned him for clawing the Spurs centre-half's cheek during Saturday's derby.

Television footage had captured Torres scratching Vertonghen as the pair clashed on the touchline five minutes into the second half. The referee, Mike Dean, was unsighted and booked Torres for a trip in the buildup to the flashpoint but his assistant Jake Collin told the governing body that he had seen "the coming together of the two players, albeit not in its entirety". Given the incident was not considered to be "extraordinary" by the FA, it felt it could not refer the matter to its new three-man panel of former referees to consider retrospective action.

That decision has baffled Villas-Boas, who has risked being sanctioned himself after expressing his disbelief before Spurs' Europa League tie against Anzhi Makhachkala in Ramenskoye on the outskirts of Moscow. "It's extremely difficult to know where to start," the Tottenham manager said. "It is almost a farcical decision. It doesn't matter to me which player or club is involved. Neither do I want to with my words put into question Fernando's integrity; neither their manager's, in trying to defend what is our position.

"I think the FA has made a decision almost a joke. It looks incredible. How can you see the images, pretty clear, and come out without punishment, on something [which] overtakes all professional behaviour? I think the decision is a disgrace. If the committee can't solve such clear images I don't think it sets out a good first example.

"I think the FA has lost all opportunity to put some sense into the images everybody saw. I'm extremely grateful for ex-refs to be able to enlighten people a little bit more, though I think most of you guys saw the incident as something that is not tolerable in football."

André Villas-Boas said the FA decision not to suspend Fernando Torres for scratching a Tottenham defender was 'almost a joke'. Photograph: Ian Kington/AFP/Getty Images

The FA's chairman, Greg Dyke, says the body has a duty to be more "proactive" in explaining its decisions in the wake of Torres avoiding sanction. "I suspect the FA needs to up its image," he told Marketing Week. "When they didn't charge Torres for scratching there was uproar [around the FA] but it was something that had been decided according to disciplinary rules. My view of the FA is that it needs to be more proactive and on the front foot [engaging with fans]."

José Mourinho, the Chelsea manager, had welcomed the decision not to sanction Torres further – the striker was later dismissed after accruing a second yellow card and will miss Sunday's trip to Norwich City – and has denounced Vertonghen's overreaction at the Spaniard's second yellow card. "I was more than confident because I think the FA defends the interest and culture of English football," he said. "And defending English football is not to protect people who cheat and simulate."

Torres had opened up his left knee as he leapt into a challenge after only 36 seconds at the National Arena and, having limped off 10 minutes later, underwent a scan on the joint on Wednesday morning, the team having returned to Cobham in the small hours after the 4-0 win over Steaua. That revealed a strain rather than rupture, with the club hoping his absence will be limited to up to three weeks rather than the six originally feared. He has been ruled out of Spain's final two World Cup qualifiers, against Belarus and Georgia, and is likely to be absent for the visit of Cardiff City and the Champions League trip to Schalke.